Relay system



A ril 19, 1938. K. H. SOMMERMEYER 2,114,852

RELAY SYSTEM Filed Feb 17, 1936 2 Sheets-Sheet 1 I I l3 1J1 4 W April '19, 1938. K. H. SOMMERMEYER 2,114,862

- RELAY SYSTEM Filed Feb. 17, 1936 2 Sheets-Sheet 2 [Rue/"Liar:

M/MM Patented Apr. 19, 1938 PATENT on-ice RELAY SYSTEM Karl H. Sommermeyer,

Evanston, Ill., assignor to G-M Laboratories, Inc., Chicago, Ill., a corporation of Illinois Application February 17, 1936, Serial No. 64,262

9 Claims.

The present invention relates generally to electrical relay systems, and relates more particu- ;larly to an improved electrical relay of the self latching type and improved operating circuits therefor.

Relays, of the type having a mechanical latch for holding the armature in an operated position often are used in systems where the relays are required to preserve the connections which they have established despite any temporary failure of power. They, also, have been used in systems where the relays are required to operate only infrequently and where it, therefore, was desirable that the relays maintain their operated positions mechanically in order to permit the magnets to be left de-energized.

It is desirable that the relay itself, in operating should interrupt its own coil circuit so as to avoid useless energization of its coil and the consequent waste of electric power. It is also desirable that the electro-magnet which operates the relay armature continue to hold the same in its operated condition until after the armature definitely has been latched or secured mechanically.

If this is not insured, the magnet may de-energize' before the armature is latched, thereby permitting the armature to return to'its original position. In so returning it re-energizes its magnet and the action is repeated again and again. This faulty self-cycling" action is sometimes referred to as buzzing or telegraphing" depending upon the speed at which it takes place. In accordance with one manner of carrying out the present invention I insure that the armature is latched before the energizing magnet is de-energized by compelling that sequence of operation mechanically. To accomplish this mechanical control of the sequence of operation I may cause the contacts which de-energize the armature magnet to be actuated by the latch itself as the latter slips into latching position. And I, also, provide a lag-loop" or.c1 osed coil time delay" circuit on the armature magnet so that the armature magnet does not release the armature until a period of time after the supply of power to the energizing coil of the magnet is discontinued.

It is desirable, also, for certain purposes to have a latching relay operate certain of its con: tacts with a time delay, that is, open or close one or more contacts after allowing a period of time to elapse after the initial energizing of the armaturemagnet. In accordance with one manner of carzring out the present invention I provide contac operated by the armature of the relay and other contacts operated by the latch itself and I vprovide interlocking electrical connections between these contacts and the magnets operating the armature and latch to cause the latch itself to delay its movement into latching position, separate the load contacts being actuated by the armature and the latch.

It is further desirable that the latch should impose a minimum of restraint upon the operation of the armature. To this end I employ the v same interlocking electrical connections above mentioned to energize the latch magnet simultaneously with the armature magnet so as to eliminate entirely all friction in the latch mechanism.

In the foregoing statements, I have used the terms "armature and latch for designating certain elements by the characteristic functions which they perform in the specific operational sequences in which they are mentioned. A latch relay may employ a symmetrical latch construction comprising two similar elements each of which elements functions either as a latch or an armature. The symmetrical arrangement permits the two functions of latch and armature respectively to be exchanged between these two similar elements and it, also, makes the device adaptable to a greater variety of control schemes.

Objects of the present invention include the provision of an improved latch relay and system for controlling it and the provision of a time de lay action in a latch relay to aid the operation of the relay itself and to provide various time delayed control functions.

Other objects and advantages will become apparent as the description proceeds.

In order better to acquaint those skilled in the art with the teachings and practice of the present invention, I now shall describe certain speci fic embodiments thereof, reference being had to the accompanying drawings forming a part of this specification and in which:

Fig. 1 is a perspective view of a latch type relay.

Fig. 2 illustrates the mechanical construction and operation of the relay, and illustrates diagrammatically one circuit arrangement in which it may be used. a

Fig. 3 is an across the line diagram or line diagram, of the circuit of Fig. 2.

Fig. 4 illustrates a system embodying the latch relay of Fig. 1 together with the circuit employing the interlocking connections which provide the time delay action .and which serve to eliminate all friction. in the latch.

Fig. 5 is an across-the-line" diagram of the circuit of Fig. 4.

Fig. 6 illustrates a modification of the system of Fig. 3. t

Fig. '1 is an across-the-line" diagram of the circuit of Fig. 6.

Referring to Figs. 1 and 2, the latch relay therein shown comprises two electro-magnets designated generally by reference numerals ii and i2. These magnets have independent magnetic circuits, separate coils 3 and H, separate armatures l5 and I6 and contacts providing separate contact gaps I9, 20, 2| and 22. These contacts consist of cantilever spring blades which carry contact buttonsat their ends as shown. Preferably the blades may be arranged in a number of stacks as shown in Fig. 1. A single stack is shown on each magnet .in Fig. 2 to facilitate the illustration. The armatures are provided with conical restoring springs 23 and 24, which aid the contact springs in tending to move the armatures into normal positions from which they may be attracted into drawn up positions by their magnets.

The two magnets II and I2 are held together by means of a metal strap or tie bar 26 in such positions relative to each other that the axes about which their armatures l5 and I6 rotate in operation are substantially parallel. Preferably the tie bar 28 is non-magnetic. The armatures l5 and is are provided with bars 21 and 28 which move therewith. These bars 21 and 28 preferably are non-magnetic and they interfere with each other in such a manner that only one of the two armatures I5 and I6 of the magnets II and I2 may occupy its normal position at one time.

Referring more particularly to Fig. 2, the bar 21 is secured to the armature i5 of the magnet H and is configured to provide a latch portion or interfering portion 3| which extends radially from the axis of rotation of its own armature l5, but extends in a direction substantially perpendicular to a similar latch portion or interfering portion 32 of the bar 28. This portion Si is located at.the end of the bar 21 between the coils i3 and it. These radial portions 3| and 32 provide the interference between the armatures which already has been referred to. They interfere so as to provide the latching or blocking action whereby one armature, when occupying its released or normal position prevents the other armature from leaving its drawn up position.

In Fig. 2, the armatures i5 and It and'their associated bars 21 and 28 shown in the full lines with the armature it of the magnet l2 in its norml or released position, and the armature l5 of the magnet |l latched thereby in its drawn-up position. The operation of the latching mechanism is substantially as follows:

When the coil 14 of the magnet I2 is energized, it attracts its armature l6 and draws it into its drawn-up position indicated in the dotted lines,

thereby bringing the radial portion 32 into the position 22-A. In moving 'into the position: 82-A, the portion 32 swings about the axis of rotation of the armature l6 and slides along the portion ll of bar 21. In so doing the end of said portion 82 moves in a direction substantially parallel to the surface of the portion 8| of the bar 21. The portion Si and the armature l5 of the magnet therefore remains substantially stationary during the motion of the armature i6 and the magnet l2. when the portion 32 reaches the position 82--A, shown in dotted lines, it no longer blocks the motion of the portion 3 I which, therefore, immediately moves under force of its own restoring spring 23 as well as under the force of its contacts i9 and 2|, to bring the portion 3| into the position 3|A shown in the dotted lines. This abrupt and positive action of the latch is due in part to the sharply squared ends of the latch portions 3| and 32. The portion 3| when in the position 3|A blocks the portion 32 in the position 32--A so as to latch the armature l6 of the magnet l2 in its drawn-up position;

' As shown in Fig. 1, the magnet conveniently may be provided with two sets of contacts to provide contact gaps l9 and 2|. In Fig. 2,'the contacts on each magnet are shown arranged in a single stack for purpose of illustration. One set of the contacts, or one contact gap, on each magnet is of the normally open type so as to be open when the armature is in its released position.

. Thus, the contact gap IQ of the magnet ii is open when the armature i5 occupies its normal or re leased position. Similarly, the contact gap 20 of the magnet I2 is open when the armature I8 thereof occupies its normal position. Contacts 2| and 22 are load contacts.

The circuit of Fig. 2 is more simply illustrated in the across-the-line diagram, or line-diagram of Fig. 3. This diagram attempts only to illusconnected in series with the normally open contact gap 20 of the magnet i2, a normally open push button switch 35 and a battery 36. SimilarLv the coil ll of the magnet 2 shunted by a resistor 30 and the combination of these two, is connected in series with the normally open contact gap IQ of the magnet push button switch 31 and the battery 36. Thus when the armature l5 of the magnet H is in its drawn-up position as shown in the full lines of Figure 2, the armature I6 of the magnet |2 will occupy its released or normal position, also, shown in the full lines and the contact gap 20 will be open. Thus, the coil l3 of the magnet cannot be energized because the contact gap 20 which 'is 0 connected in series therewith is open. However, the contact gap IQ is closed, because the armature i5 occupies its drawn-up position. If now, the push button switch 31 be closed, it will energize the coil H of the magnet l2 so as to 'draw up its armature 6, closing the contact gap 20. If, at this time, the push button 35 is in the open position, nothing happens as the result of the contact gap 20 being closed. However, when the armature I6 reaches its drawn-up position, it permits the armature l5 of the magnet l to move into its normal position as already described, thereby opening the contact gap |9 which de-energizes the coil H of the magnet I2. It is to be noted that the coil ll of the relay l2 remains energized so long as the armature l5 of the magnet occupies its drawn-up position becauseof the closed condition of the contact gap l9, and that when the coil L4 is finally de-energized by the opening of the contact gap IS. the

sequence such that the coil ll of the relay 12 may a,114,sea

not be de-energ-ized until after the latching action has been accomplished. Similarly, the push tends to prevent the button 35 may next be closed to return the armatures l5 and It to the position shown in the iull lines of Fig. 2.

The contacts which provide the contact gaps II and 22 may be of either the normally'open or the normally closed type and may be utilized for controlling one or more load circuits in any known manner.

A further provision for insuring that the relay will be positive in operation consists in subjecting the armature of the relay to a magnetic time delay which holds the armature in its picked up position for a short period of time after. the power is disconnected from its coil circuit, so as to further insure that the armature will be positively latched before it is released by its magnet; that is, to insure that the armature will be positively latched before it tends to move back to the released position.

when the coil circuit of a magnet is disconnected from the power supply by the contacts in the manner already described, the magnetic field thereof immediately begins to collapse or decay. In so doing, it generates or induces in the winding of the coil a voltage which tends to force an electric current in such a direction as to oppose the collapse or decay of the magnetic field. The voltage thus induced in the coil will produce current provided there is a closed circuit in which the current may fiow.

In the system of Figs. 2 and 3, for example, resistor 29, being connected across the terminals of the coil II, provides the closed circuit necessary for the current to flow. This circuit consists simply oi' the coil l3 and resistor 29. This current absorbs the energy of the magnetic field and dissipates it as heat resulting from the current fiowing in the resistance circuit. The fact that this current opposes the decay of the magnetic field causes the field to decay more slowly than it would if this current did not flow. The current in the coil decreases with time according to the relation expressed by the well known logarithmic decay curve. When the magnetic field decreases to that value at which it will no longer hold the armature in its drawn up position, the armature tends to move out of that position.

The rate of decay or collapse of the magnetic field may be decreased by decreasing the resistanoe which shunts the relay coil, by decreasing the residual air gap of the relays magnetic circuit (when the relay armature is in its drawn up position), or by increasing the ampere turns of excitation of the coil (by changing the coil design or increasing the voltage of its power supply). The specific means for providing this magnetic time delay of the relay forms no part of 'thepresent invention inasmuch as such means are well known in the art. Relays arranged to execute a magnetically delayed action in this manner are sometimes referred to as lag-loop relays. Another method of providing this lagloop" operation consists in providing a coiL section separate from the operating coil. This separate coil section may be short circuited, or otherwise provided with a closed circuit, and may consist oia single turn of large cross section in the form of a perforated copper slug.

The time delay action insures proper operation as follows: Assuming that the armatures l5 and ii of the latch relay of Fig. 2 are in the p sitions shown therein in full lines, the armature It may collapse of the flux and be operated by energizing its coil i4 from the battery 88 by closing the push button switch 31. The armature l6 draws up and in'so doing unlatches the armature ii in the manner already describedso that the armature I5 immediately begins to move towards'its released position. In so doing it both latches the armature l6 and opens its contact gap I! to disconnect the coil l4 from the battery. If because of misadjustment of the relay, or for any other reason, the contact gap I! should open before the latch portion ll of the armature l5 gets into position to block the latch portion 32, of the armature IS the relay can operate properly only if the armature I6 is prevented from releasing too quickly. By retarding the decay of the magnetic fiux oi the magnet l4, the release of the'armature i6 is delayed so that it is at rest in its drawn up position for a short period of time after the contact gap l9 opens. And if the contact gap I! for any reason should open before the armature it reached its picked up position, the delay in the collapse of the magnetic flux would actually prolong the period of acceleration of the armature towards its picked up position, prolong the period during which it is attracted by its magnet. Thus the magnet l4 continues to attract the armature 16 even after the battery is disconnected therefrom at the contact gap i9. Even a very short prolongation of the attraction and holding of the armature it by its magnet after the contact gap l9 opens gives the armature l5 ample time and opportunity to move to its released position so as mechanically to latch the armature IS in the latters drawn up position.

In Fig. 4, I have illustrated a new and novel circuit for a latch relay. Therein, a latch relay very similar to the oneillustrated in Fig. 2 has magnets 43 and 44 and interfering armatures 45 and 46. The armature 45 operates contacts which provides a contact gap 49 which is closed when the armature 45 is in its released position. Similarly the armature 46 operates contacts which provide the contact gap 50 of the same type. Push button switch 55 is adapted, by virtue of the circuit connections to connect the coil of the magnet 43 to a power supply 54 and, also, to connect the coil of the magnet 44 to the same power supply through the contact gap 49. Similarly a push button switch 56 is adapted to connect the coil of the magnet 44 to the power supply 54 and, also, to connect the coil of the magnet 43 to the power supply through the contact gap 50. The coils of the magnets 43 and 44 are provided with shunt resistors 51 and 58 respectively.

Assuming that the relay is in the position shown in Fig. 4 with the armature 46 occupying its released position, the push button switch 56 may be closed to operate the relay. This immediately energizes both of the coils of the latch relay. The armature 45 being substantially in its drawn up position and, therefore having a very short air gap ordinarily will take up its slack motion before the magnetic field of the magnet 44 builds up sufficiently to initiate the motion of the armature 46. The armature 45 being attracted by its magnet so as to take up the slack in the latch, removes the friction load from the armature 46 which otherwise would be imposed by the latch. This materially improves the ease of operation of the latch relay and under certain conditions reduces the power required for its operation. When the armature 45 picks up it opens the contact gap 50 soas to disconnect the power from the coil of, the magnet 43. The magnet 43 will not release the armature 46 immediately because of the lag loop" time delay provided by the resistor 51 shunting its coil. When the armature 45 does move to its released position it serves to latch the armature 45 in the latters picked up position.

Load contacts providing contact gaps and 52 may be operated by the two armatures 45 and 48. The time delay action ,iust described to which the latch relay is subjected in the system of Fig. 3 causes a delay between the closing of the push button switch 56 and the operation of the load contact gap 5! operated by the armature 45. Similarly a delay is provided between the closing of the push button switch 55 and the operation of the load contact gap 5!.

Fig-6 illustrates a modification oi the system of Fig. 4 wherein contact gaps 41 and 46 have been added to the respective magnets 43 and 44. These additional contact gaps are of the type which are openwhen the armatures operating them are in their released positions. The contact I gap 41 is connected between the push button switch 56 and the coil oi the magnet 44, and similarly the contact gap 48 is connected between the coil of the magnet 45 and the push button switch 55. Thus in Fig. 6, the push button switch 55 is adapted to connect the coil of the magnet 48 to the power supply 54 through the contact gap 48 and, also, to connect the coil of the magnet 44 to the power supply through the contact 49. Similarly the push button switch 56 is adapted to connect the coil of the magnet 44 to the power supply 54 through the contact gap 41 and, also, to connect the coil oi the magnet 48 to the power supply through the contact gap 50. The operation is as follows: Assume that the armatures 45 and 45 are in the positions in which they are shown in Fig. 6. When the push button switch 58 closes both magnet coils are energized magnet 48 attracts its armature 45 which is already held by the latch. Armature 46 picks up, and opens the contact gap 50. This disconnects the coil of the magnet 48 from the power supply 54, but the magnet 43 continues to hold up its Til armature 45 for a short time due to the delay in the collapse of the magnetic fiux imposed by the lag loop arrangement of the magnet 48. This time delay imposed by the magnet 45 delays the release of the armature 45 and the operation of its load contacts 5|. At the end of this time delay period the armature 45 releases and in so doing opens the contact gap 41 which in turn disconnects the power supply from the magnet 44. The magnet 44 then continues to hold the armature 46 for a short period oi time to give the armature 45 ample time to release and block the armature 45. When the magnet 44 finally releases the armature 45. the armature 46 drops ;against the latch which holds it in its picked up position. A similar action occurs when the push button switch 55 is closed.

' The circuits of Figs. 4 and 6 are more simply illustrated in the "across-the-line' diagrams, or line-diagrams" of Figs. 5 and 7. The line diagrams attempt only to illustrate the electrical arrangement and circuit relationships 01' the apparatus and make no attempt to illustrate any mechanical relationships of the elements or parts except by legends. The legend L1 is applied to the coil and contact gaps oi the magnet 44, while the legend L3 is applied'to the coil and contact gaps oi the magnet 43. The same reference numeral indicate the same parts in Figs. 4. 5, 6 and '7. While I have shown and described certain specific embodiments of my invention, it will be apparent to those skilled in the art that the same is by way of illustration only, and that the invention is capable of numerous variations and modifications. Therefore, I do not wish to be limited except by the scope of the appended claims I claim: I

1. In combination, a first armature, a second armature, each of said armatures having a drawn-up and a released position and being movable therebetween, a first electromagnet and a second electromagnet for said firsfand second armatures respectively, each electromagnet being adapted when energized to move its armature to the drawn-up position, interfering portions on said armatures adapting each armature when in its released position to block the movement of the other armature from its drawn-up to its released position, contacts providing a contact gap operated by said first armature which is closed when said first armature is in its released position and open when said first armature is in its drawn-up position, control means connected to the first electromagnet, said control means, also, being connected to the second electromagnet through said contact gap.

2. In combination, a first armature, a second armature, each of said armatures having a drawn-up and a released position and being movable therebetween, a first electromagnet and second electromagnet for said first and second armatures respectively, each electromagnet being adapted when energized to move its armature to the drawn-up position, interfering portions on said armatures adapting each armature when in its released position to block the movement of the other armature from its drawn-up to its released position, contacts operated by said first armature which are closed when said first armature is in its released position and open when said first armature is in its drawn up position, first control means connected to said first electromagnet, said first control means, also, being connected to said second electromagnet through said contacts, and second control means connected to said second electromagnet.

3. In combination, a first armature, 'a second armature, each of said armatures having a drawn-up and a released position and being movable therebetween, a first electromagnet and a second electromagnet for said first and second armatures respectively, each electromagnet being adapted when energized to move its armature to the drawn-up. position, interfering portions on said armatures adapting each armature when in its released position to block the movement of the other armature from its drawn-up to its released position, first contacts operated by said first armature which are closed when said first armature is in its released position and open when said first armature is in its drawn-up position, second contacts operated by said second armature which are open when said second armature is in its released position and closed when said second armature is in its drawn-up position, and control means connected to said first electromagnet through said second contacts and connected to said second electromagnet through said first contacts.

4. In combination, a first armature, a second armature, each of said armatures having a drawn up and a released position and being movable therebetween, a first electromagnet adapted when energized to move said first armature to its drawn up position. a second electromagnet ineluding a coil and adapted when said coil is energized to move said second armature to its drawn up position, said second electromagnet including means for preventing said second armature from beginning to move towards its released position until a period of time elapses after power is disconnected from said coil, first contacts operated by said first armature which are closed when said first armature is in its released posi tion and open when said first armature is in its drawn up position, second contacts operated by said second armature which are open when said second armature is in its released position and closed when said second armature is in its drawn up position, and control means connected to said first electromagnet through said second contacts and connected to said coil of said second electromagnet through said first contacts.

5. In combination, a first armature, a second armature, each of said armatures having a drawn up and a released position and being movable therebetween, a first electromagnet adapted when energized to'move said first armature to its drawn up position, a second electromagnet.

including a coil and adapted when said coil is energized to move said second armature to its drawn up position, said second electromagnet including means for decreasing the rate of collapse of the magnetic field thereof, first contacts operated by said first armature which are closed when said first armature is in its released position and open when said first armature is in its drawn up position, ,second contacts operated by said second armature which are open when said second armature is its released position and closed when said second armature is in its drawn upposition, and control means connected to said first electromagnet through said second contacts and connected to said coil of said second electromagnet through said first contacts.

6. In combination, a first armature, a second armature, each of said armatures having a drawn 'up and a released positionand being movable therebetween, a first electromagnet adapted when energized to move said first armature to its drawn up position, a second electromagnet including a coil and adapted when said coil is energized to move said second armature to its drawn up position, said second electromagnet including means tending to maintain themagnetic field thereof after said coil thereof ceases to receive electric power therefor, first contacts operated by said first armature which are closed when said first armature is in its released position and open when said first armature is in its drawn up position, second contacts operated by said second armature which are open when said second armature is in its released position and closed when said second armature is in its drawn up position, and control means connected to said first electromagnet through said second contacts and connected to said coil of said second electromagnet through said first contacts.

'7. In combination, a first armature, a second armature. each of said armatures having a drawn-up and a released position and being'movable therebetween, a first electromagnet adapted when energized to move said first armature to its drawn up position, a second electromagnet including a coil and adapted when said coil is energized to move said second armature to its I drawn up position, said second electromagnet in cluding means for opposing the collapse of the magnetic field thereof, first contacts operated by said first armature which are closed when said first armature is in its released position and open when said first armature is in its drawn-up position, second contacts operated by said second armature which are open when said second armature is in its released position and closed when said second armature is in its drawn up position, and control means including at least one source .of power for simultaneously (1) connecting said first electromagnet through said' second contacts to a source of power to energize said first magnet to operate the same, and (2) connecting said coil of said second electromagnet through said first contacts to a source of power to energize said coil to produce a magnetic field in said second electromagnet in excess of the value required for magnetically holding said second armature in its drawn up position.

8 In combination, a first armature, a second armature, each of said armatures having a drawn-up and a released position and being movable therebetween, an electromagnet for said first armature adapted when energized to move said first armature to its drawn up position, interfering portions on said armatures adapting each armature when in its released position to block the movement of the other armature from its drawn up to its released position and means operable when said electromagnet is energized for opening the coil circuit thereof and for insuring that said first armature is positively blocked against moving to its released position before it is released by said electromagnet, said means including contacts operated by said second armature and including, also, means for opposing and retarding the collapse of the magnetic field of said electromagnet.

9. In combination in a latch relay and a control system therefor, a first armature, a second armature, each of said armatures having a drawn up and a released position and being movable therebetween, an electromagnet for said first armature adapted when energized to move said first armature to its drawn up position, interfering portions on said armatures adapting each armature when in its released position to block the movement of the other armature from its drawn up to its released position, means for energizing said magnet at least momentarily, and means operable when said magnet is energized tending to insure that said first armature is positively latched by the second armature, said last means including means ing the collapse of magnetic flux of said electromagnet.

KARL H. SOMMERMEYER.

for opposing and retard- 

